Roll conveyer system



1932- E. w. HENDERSON ET AL 1,373,940

ROLL CONVEYER SYSTEM L Filed June 20, 1931 4 forward Je e/are ATTORN EYS Patented Aug. 23, 1932 UNITED STATES PATENT OFFICE EB ERT WILLIAM HENDERSON AND HARRY J. FISHER, OFCLEVELAN D, OHIO, ASSIGNOBS TO THE RELIANCE ELECTRIC & ENGINEERING OF CLEVELAND, OHIO,

. A CORPORATION OF OHIO 30m. comm svsm Application filed June 20,

This invention relates to roll conveyer systems and more particularly concerns an 1mproved and etficient system for controlling the operation of a plurality of aligned rolls constituting a conveyer.

In the rolling and shaping of metal elements such as sheet stock, rails, etc., a metallic billet is successively passed in opposite directions between a forming device usually comprising a pair of pressing rolls, the billet being carried by means known as roll-out tables as it passes in opposite directions away from the pressing rolls, One form of rollout table comprises a plurality of spaced parallel rolls disposed in substantially horizontally aligned relationship, a set of these rolls extendlng on either side of the pressing rolls and acting to carry and propel the metal element while it is being .formed. Since the metal billet under treatment must be quickly passed back and forth between the pressing rolls, it is desirable that the driving means for the rolls of the roll-out tables be controlled in such a manner that the rotation of these rolls may be quickly stopped and reversed.

With the above and other considerations in mind, it is proposed in accordance with the present invention to provide an improved system for driving the conveyer rolls of rollout tables or similar devices," this system consisting of a novel combination of elements and devices whichefiects considerable savings in the amounts of energy consumed in starting, stopping and driving the rolls as well as in the first cost of the installation. It is a further object of the invention to provide an improved control system for the conveyer roll driving apparatus which permits deceleration at a variably adjustable rate whereby the braking time may be varied to meet different operating conditions. The control system of the invention preferably includes means for bringing the conveyer rolls to a dead stop whereby the travel of the metallic sheet stock or other member carried by the rolls may be stopped atdifi'erent points, and any undesirable overrunning. of the sheets may be avoided.

In general, the above and other objects of 1931. Serial 1%. 545,076.

our'invention are carried out by emplo ing a separate alternating current motor to rive each of the rolls o fa roll-out table conveyer or similar device, and by providing a source of alternating current for operating such motors and a source of direct current for dynamically braking and stopping the motors. Suitable control means are provided for selectively applying either alternating,

current driving energy or direct current braking energy to the motors, and in one form of the invention, the control means is arranged to successively connect the several motors to the alternating current source in starting the conveyer and to simultaneously connect all of the motors to the direct current source in stopping the conveyer. The alternating current running energy and the direct current braking energy are preferably sup lied respectively by separate generators both driven by a single motor or other prime mover, and in accordance with one embodiment of the invention, the rotors of both the alternating current and the direct current generators are at all times connected to the driving motor rotor. The rate of deceleration or the braking time may be conveniently varied by changing the amount of direct current braking energy supplied to the motors and in accordance with a preferred embodiment of the invention, the field current of the direct current generator 'is altered to obtain this variation in braking.

energy. The control system may also include automatic means for governing the duration of each braking period.

In describing the invention in detail, reference will be made to the accompanying drawing in which the single figure represents, in a diagrammatic and simplified manner, one embodiment of our invention as applied to the roll conveyer of a roll-out table.

Referring to the drawing. the roll-out table is shown as comprising a plurality of'spaced parallel rolls 1, 2, 3 and 4 carried by a frame 5 or other suitable means, the rolls extending in substantially horizontal alignment on one side of the pressing or forming device 6 which may comprise a pair of vertically s aced pressing rolls. It should be understoo that a similar set of spaced parallel conveyer rolls extends horizontally away'from the opposite side of the pressing device 6 from that on which the rolls 1 through 4 are located, and a set of rolls 1', 2, 3' and 4' have been indicated in this position. Since the rolls of each set are driven and controlled either by the same control system or by substantially'identical control means, the driving and control ing rolls elther directly or through the speed changing gears and/0r clutches represented at ll. The" motors 7 through 10 may be of any suitable type but preferably comprise alternating current induction motors.

The source of energy for driving motors 7 through 10 preferably comprises an alternating current generator AI driven by a motor M to which the generator A may be directl connected, as shown. The motor M is'pre erably of the variable speed type. The roll motors 7 through 10 and the generator A are preferably of the polyphase type, and energy from the generator may be applied to the bus bars or other conductors 12 leading to the roll motors ineither normal or reverse phase rotation through the switches F and R. The motors 7 through 10' may be respectively connected to the bus bars through the separate switches 13, 14, 15 and 16. Direct current braking energy from a generator D may be connected across/the bus bars 12 through the braking switch B, and the braking period, as determined by the time during which this switch is closed, is governedby suitable automatic means such as a timing device T. The direct current generator 1) is preferably driven by the motor M and in the disclosed embodiment is directly connected to this'motor. The operation of.-the various running and stopping switches is governed by a manually operable device such as the drum contactor represented at G.

In the operation of our improved system, the contactor C may be moved to its forward or reverse position to start the rolls with the result that one of the switches F or B is closed and alternating current energy of either normal or reverse phase rotation is thereby applied to the busbars 12. -At the same time, the switch 13 is closed to connect the roll motor 7to the bus'bars 12 and thereafter the switches 14, 15 and 16 are successively closed to successively connect the motors 8, 9 and 10 to the bus bars as hereinafter more fully described. When the manually operable contactor C is moved to its central stop position, the previously closed alternating current switch F or R opens, and the roll motor switches 13,14,15 and 16 also open. The braking switch B then closes to apply direct current braking energy to the bus bars 12 for a predetermined period governed b thetiming device T and upon the closing 0 the switch B, all 0% the motor switches 13 through 16 are closed simultaneously to apply braking direct current to the motors 7 throu h 10.

Referring more indetai to the operation of the improved system shown, assume that the rolls 1 throu h 4 are at a stand still and that it is desire .to start these rolls in the forward ornormal direction of rotation.

The manually operable contactor C is moved to the forward position in which the drum contacts 17 connect the contacts 18 and 19, the other drum contacts-61 and 72 being removed from their respective stationary contacts 19, 62, 73 and 74 in this position of.

tion through the contacts 29, 30 and 31. The

closing of the switch F opens its back contacts 33 and 34 and so prevents the energization of either the operatin coil 35 of the switch R orthe operating co1l36 of the brak- I i ing switch B. The closing of the contacts 32 of theforward switch F energizes the operating coil 37 of the roll motor switch 13 through a circuit including the wires 28, 38 and 39, the coil 37, the wires 40, 41 and 42, the contacts 32, the wires 43 and 23, the contacts 18, 17 and 19 and the wire 22: The

energization of the coil 37 closes the switch 13 and the roll motor 7 is accordingly energized and starts to drive its roll 1.

As soon as the switch 13 closes, its contacts 44 complete an energizing circuit for the o erating coil 45 of the swltch 14 through t ewires 46, 47, 48 and 49 and the switch 14 is then closed tooenergize the motor 8 and start a the roll 2. The contacts '50 of the switch 14 complete an en'ergization circuit for the op-- erating'coil 51 of the switch 15 through the wires 52, 53, 54 and 55, and the switch 15 accordingly closes and energizes the motor 9 whereby the roll 3 is started. The contacts 56 of the switch 15 complete an energizing circuit for the operating coil 57 of the*switch 16 through the wires 58, 59 and 60 and the switch 16 is thus closed to energize the motor 1 10 which starts to drive the re 14.

When it is desired to stop the operation of the rolls, as for example at the end of a forward run of the sheet stock or billet, the drum contactor C is moved to the central ,or stop position. In this position, the drum contacts 17 disengage and" disconnect the stationary contacts 18 and 19 and the L drum contacts 72 engage and connect the stationary contacts 73 and 74. The'opening of the contacts 18 and 19 deenergizes the operating coil 21 of the forward switch-F and this switch opens. The rollmotor switches 13 through 16 are accordingly opened, their operating coils 37, 45, 51and 57 being deenergized when the contact 32 of the switch F opens, and the motors 7 through are deenergized but continue to rotate due to the momentum of the rolls 1 through 4 and the moving sheet or billet carried thereby.

. D to the bus bars 12 through circuits which 1 97 and 98; thus when the operating coil 36 The closing of the contacts 72, 73 and 74 of the contactor C completes an energizing circuit for the operating coil 36 of the braking switch .B, which circuit may be traced as follows; from the direct current control energy source DC, through the switch'75, the wires 76 and 77, back contacts 34 of the forward switch F, wire 78, back contacts 34' of the reverse switch R, wire 79, operating coil 36, wire 80, contacts 81 ofthe timing device T, wire 82, contacts 73, 72 and 74 of the contactor C and wire 83. The energization of the coil 36 closes the switch B and the contacts 84, 85,- 86 and 87 thereof connect direct current energy of the generator are clearly shown in the drawing. The closing of the contacts 88 and 89 of the switch B simultaneously energizes the operating coils 37, 45, 51 and 57 of the roll motor switches 13, 14, and 16 and accordingly closes these switches and simultaneously applies direct current braking energy to all of the motors 7 through 10 and quickly brings these motors and their conected rolls to rest. The energizing circuit for the operating coils of the braking switches 13 through 16 includes the wires 22 and '90, the contacts 88 of the switch B, the wires 91, 41 and '40, the wires 49 and 48, the wires and 54, the wire 60, the coils 37, 45, 51 and 57 in parallel, the wires 59 and 91, 53 and 92, 47 and 93, the contacts The timing. device T may take any suitable formand is essentially designed to maintain its contacts 81 closed until the operating coil 36 of the braking switch B has .been energized for a predetermined interval, this interval corresponding to the time required to bring all of the rolls 1 through 4 and the billet or sheet stock carried thereby to a dead stop. As shown, the contacts 81 of the device T are normally maintained closed by a spring'95 or equivalent means, and the energization of the operating coil 96 of'the device tends to open these contacts against the action of this I spring. The opening of the contacts 81 may be delayed by any suitable means such as the dash pot 97. The operating coil 96 is con-- nected in parallel with the operating coil 36 of the braking switch B through the wires 89 of the switch B and the wires .94, 38 and of,the switch B is energized to close this Since the energizing circuit for the operating coil 96 of the timing device T does not. include the contacts 81 of this device, the C011 96 remains energized and the contacts 81 open.

until the drum contactor C is moved away from the stop position. The opening of the braking switch B opens its contacts 84, 85, 86, 87, 88 and 89 and accordingly, disconnects the direct current braking energy from the bus bars 12 and deenergizes the operating coils of the roll motor switches 13 through 16.

The degree of braking energy applied to the roll motors 7 through 10, and accordingly, the rate of deceleration or the braking t me, may be economically varied by chang-. ing the output of the direct current generator D. This may be conveniently accomplished by changing the field current of this generator by means of the field rheostat 100. Thus, the system may be arranged to stop the conveyer rolls in a redetermined time with various weights of sheet stock or other material thereon, or the braking time may be varied as desired to stop the material conveyed at any required point. This variability of the braking time is particularly advantageous on adjustable speed roll-out tables,

where the speed range may be comparatively large.

When it is desired to start the rolls 1 through 4 in the reverse direction, the drum contactor C is moved to the reverse pos tion, and its movable contacts61 engage and connect the stationary contacts 19 and 62. The closing of'these contacts 19,. 61, and 62 completesan energizing circuit for the operating coil 35 of the reverse switch R through the wires 22, 63 and 64, the back contacts 33 of the switch F and the wires 65, 27 and 28. The reverse switch R is accordingly closed and supplies alternating current of the reverse phase rotation from the generator A through the contacts 66,67 and 68 to the bus bars 12. The closing of the contacts 69 of the reverse switch R supplies energy through the wires 70, 71, 42 and 41 to the operating coil 37 of the switch 13, whereby this sw tch is closed and the motor 7 is operated to start the roll 1 in the reverse direction. The switches 14, 15' and 16 are successively closed to successively energize the motors 8, 9 and 10 and thus start the rolls 2, 3 and 4 in the reverse direction, the energizing circuit for the roll motor switch operating coils be ng as traced above in connection with forward operation.

From the description given, it will be seen that in starting the roll driving motors in either direction, the motors are separately and successively connected to the alternating current generator A is limited to a compara- 1 tively low value and the capacity of the generator A may be considerably less than that required to start all of the roll motors simul- 15 taneously. It should be understood that in many commercial installations, large numbers of rolls each driven by a separate roll motor may "be used, sad that in such cases, the motors may beconveniently controlled in groups, each of theswitches 13, 14,15 and 16 controlling one group of two or more motors. In the appended claims, the statement that alternatin current is successively supplied to each 0 the roll drive motors in turn means that such current is successively supplied to each individual motor or to difierent groups of two or more motors. It is not es-' sential that all of the rolls 1 through 4 be started simultaneously; thesuccessive starting of the rolls accelerates the sheet stock or billet at a suitable rate. In stopping the rolls, the application of direct current braking en ergy to-all of the roll motors simultaneously brings-the rolls and the sheet stock to a dead stop and .thus prevents any undesirable overrunning of thestock which might result in injury to the operator or apparatus or the sliding of the stock ofi the roll-out table. The rate of deceleration of the stock by the direct current braking energy may be variably adjusted to any desired value by means of the field rheostat 100. By means of this adjustable feature, the rate of-deceleration may be so fixed with respect to the load carconveyer rolls and the sheet stock during retardation and accordingly, the surface of the: stock is not scratched or blemished.

The direct current generator 1) employed cording] the cost of this generator i'scomparative y low. Since the two generators A and D never draw power from'the motor M simultaneously, an inexpensive motor of comparat ively low power may be used. Further, the dIIGClLCOIIDGCtlOIl of the alternating cur rent and the direct current enerator rotors to the motor-rotor shaft a ds-considerable momentum to the rotating parts of the generatmg apparatus and accordingly, prevents undue deceleration of these parts upon the aplication of sudden braking or starting loads.

7 us, when the direct current braking eneris applied to the roll motors, the rotor of o alternating current generator A (which ried that there is no slippage between the .motors.

is preferably ofthe high speed type and a'ca aeraoeo is not generating powerduring the braking operation) acts as a fly wheel to assist the motor M in driving. the generator D. In a lik manner, when alternating current driving energy, is supplied from the generator A to start the roll motors, the then idle rotor of the direct current generator D acts as a fly wheel and assists the motor M in driving the generator A.

The motor M is preferably of the variable speed type, arheostat 101 or other suitable means being provided to vary the ipeed thereof. Thus, the operating speed 0 the roll-out table may be readily varied over a wide range.

Due to the successive separate energization of the several roll motors in starting the conveyer, as provided by our improved system, the motor M need have a capacity only suficient to furnish the power required for starting a portion ofthe conveyer.

Although the invention in its broader aspects is not limited to the use of any particular type of motors for driving the conveyer'rolls, it is referred to employ standard squirrel cage induction motors having low resistance rotors for this purpose because of the low cost of such motors. The desirable flux-torque relations obtained with direct current dynamic braking cause a comparatively low heating of the roll motors during the braking motors of comparatively small capacities. We claim:

1. In apparatus of the character described,

current'successively to each of saidroll mo-' tors forv causingl'the rotation of said motors and meansg'for at other times connecting a source of d rect current to all of-said rollmotors simultaneously retard and stop said paratus the'cha'racter described,

operation and makes possible the use of roll in combination with aplurality of alternating current motors each connected to drive one roll of; a inu'lti-roll conveyer of the type adapted toconvey a single element which simultaneouslyenga es aplurality of the conveyer rolls, means or at times connecting a source of alternating current successively to each of: 7

said roll motors for; causing the rotation of said motors, means for at other times connecting asource of direct'cur'rent to -all of said roll motors simultaneously and a single means for maintainin all of said direct current source connecte predetermined time interval. 3. In apparatus of the character described, in combination with a plurality of alternating current motors each connected to drivelone roll of a multi-roll conveyer, means for at times successively, supplying alternating ourto said motors for a rent energy to each of said motors in turn, means for at other times supplying direct current energy to all of said motors simultaneously to retard said motors and means for varying the amount of direct current energy so supplied.

4. In apparatus of the character described, in combination with a plurality of alternating current motors each connected to drive one roll of a multi-roll conveyer, means for at times successively supplying alternating current energy to each of said motors in turn, means for at other times supplying direct current energy to all of said motors simultaneously to retard said motors, means for varying the frequency of said alternating current energy to change the speed of said motors and means for varying the amount of direct current energy supplied-to vary the rate of retardation of said motors.

5. In apparatus of the character described, in combination with a plurality of alternating current motors each connected to drive one roll of a multi-roll conveyer of the type adapted to convey an element which simultaneously engages a plurality of the conveyer rolls, means for at times successively supplying alternating current energy to each of said motors in turn, means for at other times supplying direct-current energy to all of said motors simultaneously to retard said motors, a single means for limiting the time of said application of direct current energy to a. predetermined interval and means for varying the magnitude of the direct current energy so supplied to vary the rate of retardation of said motors.

tures.

EBERT WM. HENDERSON. HARRY J. FISHER.

6. In apparatus of the character described,

in combination with a plurality of alternating current motors each connected to one roll of a multi-roll conveyer, an alternating current generator, a direct current generator, 2. single motor directly connected to drive both of said generators, means for at times connecting said alternating current generator to said motors in normal phase rotation, means for at times connecting said alternating current generator to said roll motors in reverse phase rotation, means for at other times connecting said direct current generator to said roll motors and means for varying the output of said direct current generator.

7 In apparatus of the character described, in combination with a plurality of alternating current motors each connected to one roll of a multi-roll conveyer, an, alternating current generator, a direct current generator, a single motor directly connected to drive both of said generators, means for at times successively connecting said alternating current generator to each of said motors, means for at times connecting said direct current generator to all of said motors simultaneously for a predetermined time interval, means for varying the output of said direct current gen- Q QIER'RWHUATE @F wmmrm. v

a Patent No. 3,8733%. Anni 2L3, 1932.

mam WKLLHAM HENDERWN Ki'i AIL.

M is hereby certified that ermr fififlfS iii the inted! speciiicatiim mi we abawe numbered patent requiring coir ct'iiini as ioiiows: Page 4, Kine i2, claim '2, strike out me words "ail oi" and-insert the sum hem-e "said" in Him 124;

and that the said mam Patent simuid be mad with this comrectian tinemiai kiwi ma same may wmim'm w the mm oi the case in the Pawn fiiiice,

Sied and syeaieii this 29th day 05 November, A. 11). i932.

M J; Iii mm, (Smfl) Acaing Qissimmer 0i Paieiiis., 

